From nobody Thu May 2 02:30:54 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1569061099; cv=none; d=zoho.com; s=zohoarc; b=RgvelWPUf9DVnY9MQxE/YG4Li3E3Cf7lkVj8Kc+x2Tb0sEBLLlhfE/1oRinkamWmWT3yd34MEkFwoHg92JbSkJjYKn5TdM3S7GUv4UKxjYk9OEaeEdBpZzFjuo+2NME4HmtT0Xj69uDlCU83GzfOJ7Jykjrw+QRRGEq6sR2BGN8= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zoho.com; s=zohoarc; t=1569061099; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:Sender:Subject:To:ARC-Authentication-Results; bh=iQ5nCmfAo3RfWMzOtS6u82c7XOGbPVl/bRFKz529Tsw=; b=Ct6ZmS3DD7m7oMSeFZ4x3IfA4pa5RXNYPPYStnbNUXOGQ0dUnJOKs2Wy0CLzDrCRUfpu8NuSUCWwkR8WdRGGodWZwCIHax0YbS9DGq+04CimT4JNAemb9YSqFGLFtkNRqAmxnwuj4KHcqkfhOc90Ew6efHpaa/BEAIZnx6cpUFM= ARC-Authentication-Results: i=1; mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 15690610994271012.6725118126459; Sat, 21 Sep 2019 03:18:19 -0700 (PDT) Received: from localhost ([::1]:40692 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iBcSw-0004TN-Os for importer@patchew.org; Sat, 21 Sep 2019 06:18:10 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:45284) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iBcS2-0003wb-44 for qemu-devel@nongnu.org; Sat, 21 Sep 2019 06:17:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iBcS0-0006J0-Fv for qemu-devel@nongnu.org; Sat, 21 Sep 2019 06:17:13 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55782) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iBcS0-0006Ib-Ah; Sat, 21 Sep 2019 06:17:12 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 4401B18C4275; Sat, 21 Sep 2019 10:17:11 +0000 (UTC) Received: from x1w.redhat.com (ovpn-204-61.brq.redhat.com [10.40.204.61]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4C9DB5C1B5; Sat, 21 Sep 2019 10:17:06 +0000 (UTC) From: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= To: qemu-trivial@nongnu.org, qemu-devel@nongnu.org Subject: [PATCH] hw/ptimer: Assert next_event is newer than last_event Date: Sat, 21 Sep 2019 12:17:03 +0200 Message-Id: <20190921101703.17935-1-philmd@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.6.2 (mx1.redhat.com [10.5.110.62]); Sat, 21 Sep 2019 10:17:11 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , Dmitry Osipenko , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Paolo Bonzini Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" If the period is too big, the 'delta * period' product result might overflow, resulting in a negative number, then the next_event ends before the last_event. This is buggy, as there is no forward progress. Assert this can not happen. Signed-off-by: Philippe Mathieu-Daud=C3=A9 --- hw/core/ptimer.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/hw/core/ptimer.c b/hw/core/ptimer.c index d58e2dfdb0..88085d4c81 100644 --- a/hw/core/ptimer.c +++ b/hw/core/ptimer.c @@ -125,6 +125,9 @@ static void ptimer_reload(ptimer_state *s, int delta_ad= just) =20 s->last_event =3D s->next_event; s->next_event =3D s->last_event + delta * period; + /* Verify forward progress */ + g_assert(s->next_event > s->last_event); + if (period_frac) { s->next_event +=3D ((int64_t)period_frac * delta) >> 32; } --=20 2.20.1